Condensation on polycarbonate roof (ed.)

Hi all,

We have just finished a rear extension. As part of that we created a small polycarbonate area (9m^2). The roof is 10mm polycarbonate sheets.

On three sides are insulated walls and the front is plywood frame and a front door type door. Then there is fence panel and fence gate Infront of it (looks better and keeping neighbours happy).

I'm noticing that the sheets are literally dripping water because of condensation. My builder has said this will be the case this year and next year it will be less as the walls and concrete floor are all wet. I am told there will always be condensation... varying amounts by different people.

Some of the plywood is also showing signs of mould, between one of the insulated walls and my extension there is a 50cm gap (see picture) which also has a plywood frame.


(No door on the house brick wall).


So my question is..

1. How do I minimise condensation in this area as I wanted to make this into a storage area and useable throughout the year and store home grown produce....
2. Is it a good idea to paint all the plywood and wood inside to protect it?
3. We have a consumer unit (powers the extension)/light /socket in this area, should I be concerned?
4. any other tips or advice?


Thanks

Can you upload a pic please rather than link to screwfix forum?

Sorry, sorted with pictures.

Do you have any ventilation for warm air to escape and not condensate on the roof panels???

We have some, how much would be enough?

Thanks

makingalife said:

We have some, how much would be enough?

Thanks

Click to expand...

I would drill 2 x 4” holes at the front bottom of the structure, covered with mesh and a vent.

Then another 1 x 4” hole above the door and again covered in mesh and a vent cover...the mesh will stop any bugs getting in and then should be enough.

if you have a timber wall directly opposite the door, then maybe another 4” vent there too....

or you could put in a bathroom extractor fan on a timer switch set to run for 5mins every hour to remove any damp condensation within, again just a 4” extractor would be fine.

Thanks, great advice.

I will add more vents.


If I add vents and put some kitchen units there, will they start to rot/get ruined because of the condensation?

Thanks

makingalife said:

Thanks, great advice.

I will add more vents.


If I add vents and put some kitchen units there, will they start to rot/get ruined because of the condensation?

Thanks

Click to expand...

Not if it’s vented properly with a good flow of air...

also I notice on the wall a white vent going into that lean too, is that a toilet, tumble dryer vent, if so then that’s why your also getting lots of condensation. So the new vents will help eradicate the issue

The greenhouse doesn't get much condensation, there is a small W/C on the other side of that vent.

Used occasionally.